34 research outputs found

    Symmetry-Driven Valleytronics in Single-Layer Tin Chalcogenides

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    The concept of valleytronics has recently gained considerable research attention due to its intriguing physical phenomena and practical applications in optoelectronics and quantum information. In this study, by employing GW-BSE calculations and symmetry analysis, we demonstrate that single-layer orthorhombic SnS and SnSe possess high carrier mobility and exceptional excitonic effects. Especially, these materials display spontaneous linearly polarized optical selectivity, a behavior that differs from the valley-selective circular dichroism observed in the hexagonal lattices. Specifically, when subjected to a zigzag polarization of light, only the A exciton (stemming from the X valley) becomes optically active, while the B exciton (arising from the Y valley) remains dark. The armchair-polarized light triggers the opposite behavior. This selective optical excitation arises from the symmetry of the bands under mirror symmetry. Additionally, the study reveals a strong coupling between valley physics and ferroelectricity in layered tin chalcogenides, enabling the manipulation of electronic transport and exciton polarization. Layered tin chalcogenides thus emerge as promising candidates for both valleytronic and ferroelectric materials

    Effects of different fibre sources in pig diets on growth performance, gas emissions and slurry characteristics

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    The effects of different fibre sources in pig diets on growth performance, ammonia (NH3), hydrogen sulphide (H2S), greenhouse gas (GHG) emissions and slurry characteristics was studied on 20 crossbred pigs [Duroc x F1 (Landrace x Yorkshire)]. The experimental diets included one low-fibre (LF) diet without maize distiller’s dried grains with solubles (DDGS), brewer’s grain (BG) and coconut cake (CC) and 3 high-fibre (HF) diets with maize DDGS or BG or CC. The experiment was conducted according to a completely randomized design with 5 replications and lasted 62 days. In the growing period and the overall, pigs fed diets LF and HF-DDGS had higher average daily gain (ADG) compared to pigs fed diets HF-BG and HF-CC (P 0.05), while N and P excretions (g/head/day) were greater for diet HF-CC than for diet LF (P < 0.05). The CO2 emission was greater for diets HF-BG and HF-CC than for diets LF and HF-DDGS (P 0.05). In both periods, CH4 emission was lower in diet LF than in diet HF-BG and HF-CC (P < 0.05), while NH3 emission was higher for pigs fed diet LF than pigs fed HF-BG and HF-CC (P < 0.05). The H2 S emission was not affected by diets in both periods. In conclusion, different fibre sources in pig diets may be a practical method to alter growth performance, slurry characteristics and NH3, GHG emissions

    Premnaodoroside A and 10-o-trans-p-methoxycinnamoylcatalpol, two iridoid glycoside derivatives from the leaves of Premna integrifolia L

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    From the leaves of Premna integrifolia L. two iridoid glycoside derivatives premnaodoroside A (1) and 10-O-trans-p-methoxycinnamoylcatalpol (2) were isolated. Their chemical structures were elucidated by means of ESI-mass MS, 1H-NMR, 13C-NMR (CPD and DEPT), HSQC, and HMBC spectra in comparison with the literature. This is the first report of 1 and 2 from P. integrifolia species

    Chemical constituents from fruits of Hydnocarpus hainanensis Merr. (Flacourtiaceae) in Vietnam

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    Five compounds were isolated from the fruits of Hydnocarpus hainanensis Merr. Sleum. (Flacourtiaceae). Their structures were determined by spectroscopic analysis including MS and NMR. The isolates were identified as taraktophyllin (1), hydnocarpic acid (2), 3,4-dihydroxybenzyl alcohol (3), 3,4-dihydroxybenzoic acid (4) and 3-hydroxy-4-methoxybenzoic acid (5)

    Simultaneously induced mutations in eIF4E genes by CRISPR/Cas9 enhance PVY resistance in tobacco

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    Tobacco is an important commercial crop and a rich source of alkaloids for pharmaceutical and agricultural applications. However, its yield can be reduced by up to 70% due to virus infections, especially by a potyvirus Potato virus Y (PVY). The replication of PVY relies on host factors, and eukaryotic translation initiation factor 4Es (eIF4Es) have already been identified as recessive resistance genes against potyviruses in many plant species. To investigate the molecular basis of PVY resistance in the widely cultivated allotetraploid tobacco variety K326, we developed a dual guide RNA CRISPR/Cas9 system for combinatorial gene editing of two clades, eIF4E1 (eIF4E1-S and eIF4E1-T) and eIF4E2 (eIF4E2-S and eIF4E2-T) in the eIF4E gene family comprising six members in tobacco. We screened for CRISPR/Cas9-induced mutations by heteroduplex analysis and Sanger sequencing, and monitored PVY(O) accumulation in virus challenged regenerated plants by DAS-ELISA both in T0 and T1 generations. We found that all T0 lines carrying targeted mutations in the eIF4E1-S gene displayed enhanced resistance to PVY(O) confirming previous reports. More importantly, our combinatorial approach revealed that eIF4E1-S is necessary but not sufficient for complete PVY resistance. Only the quadruple mutants harboring loss-of-function mutations in eIF4E1-S, eIF4E1-T, eIF4E2-S and eIF4E2-T showed heritable high-level resistance to PVY(O) in tobacco. Our work highlights the importance of understanding host factor redundancy in virus replication and provides a roadmap to generate virus resistance by combinatorial CRISPR/Cas9-mediated editing in non-model crop plants with complex genomes

    Terpenoids from leaves of Viburnum sambucinum Reinw. ex. Blume (Caprifoliaceae)

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    Six compounds were isolated from the leaves of Viburnum sambucinum Reinw. ex Blume (Caprifoliaceae).  The structures of the isolates were determined by spectroscopic analysis including MS and NMR. Accordingly, the isolated compounds were identified as a-amyrin (1), ursolic acid (2), 3β,28-dihydroxy-urs-12-ene (3), oleanolic acid (4), 16β-hydroxylup-20(29)-ene-3-one (5) and trans-2-phyten-1-ol (6)

    Workplace wellbeing in community pharmacy practice: A cross-sectional study in Can Tho, Vietnam

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    Background: Among pharmacy workers, low workplace wellbeing can lead to reduced effectiveness. However, to date, studies on this issue are limited within the community pharmacy setting in Vietnam. Objectives: This study was conducted to identify the component aspects of workplace wellbeing and their associations with demographic characteristics. Methods: The cross-sectional descriptive study was conducted in Can Tho, Vietnam. Self-administered questionnaires were hand-delivered to all pharmacy workers working at selected community pharmacies. The workplace wellbeing scale comprised 18 items. Results: In total, 382 pharmacy workers participated in this study. Factor analysis revealed three fundamental aspects to workplace wellbeing: Factor 1 – perceived self-worth and job satisfaction, Factor 2 – positive emotions with work, and Factor 3 – negative emotions with work. Factor 1 showed a positive correlation with Factor 2, with a correlation coefficient (ρ) of 0.509, while both Factor 1 (ρ = −0.399) and Factor 2 (ρ = −0.416) demonstrated negative correlations with Factor 3. Higher income was associated with higher positive emotions with work (P = 0.008), higher perceived self-worth and job satisfaction (P = 0.013), and lower negative emotions with work (P < 0.001). Conclusion: Workplace wellbeing of pharmacy workers in their professional environments was associated with financial aspects. These findings suggest that policies aimed at improving income for pharmacy workers could bring benefits to enhancing job satisfaction and workplace wellbeing
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